An 82-year-old former street boss in the Boston mafia will go back to prison after federal prosecutors uncovered what they described as a plan to kill several federal officials associated with his criminal case .

Ralph DeLeo was accused of violating the terms of his supervised release in three ways : that he lied to federal agents, that he communicated with other convicted felons and that he possessed drugs. Under the terms of the agreement, prosecutors dropped the third violation, possession of controlled substances.

U.S. District Court Judge Stacey Neumann accepted the terms of the plea at a hearing Friday, court records show. DeLeo will now spend two years in prison, followed by a year of supervised release.

Investigators began looking into DeLeo in May after receiving a tip tha

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